Solving Two Homework Problems: Work, Power, and Speed Calculations

Click For Summary

Homework Help Overview

The discussion revolves around two physics problems related to work, power, and speed calculations. The first problem involves a skier being pulled up a slope, while the second concerns a student climbing a rope. Both scenarios require understanding of work and power concepts in a physics context.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster expresses uncertainty about the relevant equations and how to begin solving the problems. Some participants suggest reviewing class materials related to work, energy, and power. Others inquire about the components of forces involved in the skier's problem, hinting at the use of trigonometry.

Discussion Status

The discussion is ongoing, with participants exploring different aspects of the problems. Some guidance has been provided regarding the equations and the need to analyze forces, but there is no clear consensus or resolution yet.

Contextual Notes

The original poster mentions a lack of prior knowledge due to missing class, which may affect their understanding of the concepts involved. There is also an indication that they are unsure about the equations necessary for solving the problems.

kello2008
Messages
2
Reaction score
0
FIRST PROBLEM

Homework Statement


A skier of mass 70 kg is pulled up a slope by a motor-driven cable. (a) How much work is required to pull him 60m up a 30 degree slope (assumed frictionless) at a constant speed of 2.0 m/s? (b) What power must a motor have to perform this task?


Homework Equations


I am not sure what they should be.



The Attempt at a Solution


I do not know where to begin and with what equations.


SECOND PROBLEM!

Homework Statement


A 50.0-kg student climbs a 5.00-m-long rope and stops at the top. (a) What must her average speed be in order to match the power output of a 200 W light bulb? (b) How much work does she do?


Homework Equations


I do not know where to begin.


The Attempt at a Solution


I do not have an attempt.


Thanks for your time and help.
 
Physics news on Phys.org
What have you been doing in class before you got these questions? Surely you have been given some formula by the teacher. I would start by reviewing work, energy and power in whatever resources you have (i.e. textbooks, classs notes etc).
 
The only equation we have been given is W= |F||d|costheta

and I am not sure how to plug the information into the equation. I missed class the day that we did example problems.
 
What is the component of the skiers weight parallel to the slope (simple trigonometry)? Once you have worked out that force you can multiply it by the distance traveled to find out the work.
 

Similar threads

Problem with the power of car
  • · Replies 3 ·
Replies
3
Views
1K
A Physics 11 Elevator Work/Power Problem
  • · Replies 3 ·
Replies
3
Views
4K
How Do You Calculate Power in These Physics Problems?
  • · Replies 5 ·
Replies
5
Views
2K
Skiing Up a Slope: Solving Work & Power Requirements
  • · Replies 9 ·
Replies
9
Views
2K
Homework: Calculate the work done to accelrate a car
  • · Replies 1 ·
Replies
1
Views
1K
Homework help: Work and Energy: Spring
  • · Replies 3 ·
Replies
3
Views
2K
Avg Power in a Rotational Energy/Work Problem
  • · Replies 6 ·
Replies
6
Views
2K
Angular Speed/Torque Homework: Hubble Telescope | Answers Provided
  • · Replies 10 ·
Replies
10
Views
3K
Homework help: Work and Energy, Free fall
  • · Replies 6 ·
Replies
6
Views
2K
What is the Power Output of Gravity?
  • · Replies 6 ·
Replies
6
Views
2K